To more fully elaborate the clinical, tissue-cutural, histochemical, biochemical, ultrastructural, radioisotopic electrophysiologic and immunologic abnormalities of patients with the various myopathies and certain other neuromuscular disorders. To further sub-classify patients in each category using those parameters. To seek pathogenic mechanisms, using a variety of different techniques including ones listed above, applied to the patient's body fluids and tissues, particularly to the muscle biopsy specimens. To tissue-culture human abnormal muscle in order to reincarnate the disease in culture and then to treat it in vitro. To induce, by chemicals and by immunologic means, models of human myopathies in animals and in tissue-cultured human and animal muscle.